Space telegraphy.



No. 802,417. PATENTED OCT. 24, 1905. J. S. STONE.

SPACE TELEGRAPHY.

APPLICATION FILED 21:13.23. 1904.

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PATENTBD 001 251905.

J. S. STONE. SPACE TELEGRAPHY.

APPLICATION FILED FEB.23.190&.

2 SHEETS-SHEET 21 UNITED STATES PATENT OFFICE.

JOHN STONE STONE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO WILLIAM W.SWAN, TRUSTEE, OF BROOKLINE, MASSACHUSETTS.

SPACE TELEGRAPHY.

Specification of Letters Patent.

Patented Oct. 24, 1905.

Application filed February 23, 1904. Serial No. 194,649.

To a whom it 'nuty concern:

Be it known that I, JOHN STONE Sronn, a citizen of the United States,and a resident of Cambridge, in the county of Middlesex and State ofMassachusetts, have invented a certain new and useful improvement inSpace Telegraphy, of which the following is a specification.

This invention relates to the art of transmitting intelligence from onestation to another by means of electromagnetic waves Without the use ofwires to guide the waves to their destination; and it relates moreparticularly to systems for receiving signals transmitted by such waves.

The object of the present invention is to so adjust the elevatedconductor system of a wireless or space telegraph receiving stationrelative to an associated tuned or resonant receiving circuit orcircuits that, first, a persistent train of electromagnetic Waves of apredetermined frequency impinging upon the elevated conductor shallcause the associated circuit or circuits to respond energetically; that,second, a persistent train of electromagnetic waves of frequency otherthan said predetermined frequency impinging upon the elevated conductorshall cause the associated tuned or resonant circuit or circuits torespond but feebly; and that, third, abrupt or impulsive electric forcesacting upon the elevated conductor shall likewise produce but feebleresponse in the associated tuned or resonant circuit or circuits.

The first and second objects of this invention may be attained by givingthe elevated receiving conductor system a pronounced fundamental of afrequency which is the same as that to which the associated tuned orresonant receiving circuit or circuits is attuned.

The first and second objects of this invention may therefore be attainedby placing a suitable inductance or capacity in the elevated conductornear its connection to earth,'if it be an earthed elevated conductor, orat the center of a receiving conductor, if it be an unearthed conductor,as thereby the receiving conductor will be given a pronounced andpredetermined fundamental much as a stretched string may be given apredetermined and more pronounced fundamental by the addition of asuitable load at its center.

1f therefore the loading inductance or capacity added be made such as togive the elevated conductor system a fundamental whose frequency is thesame as that of the associated tuned or resonant receiving circuit orcircuits, the first and second objects of the invention will berealized.

,But this simple device is not sufficient to accomplish the third objectof the present in vention, and for that purpose it is necessary to givethe elevated conductor natural periods of vibration whose frequenciesare different from that to which the associated tuned or resonantreceiving circuit or circuits is attuned, and this in turn I accomplishby giving the elevated conductor system a plurality of degrees offreedom by any one of a variety of means.

In other words, I accomplish the third ob ject of this invention byemploying an elevated conductor system having natural rates of vibrationdifferent from the frequency of the Waves the energy of which is to bereceived, and consequently different from the frequency to which theassociated tuned or resonant receiving circuit or circuits is attuned.

The invention may best be understood by having reference to the drawingswhich accompany and form a part of this specification, and whichillustrate diagrainmatically arrangements of apparatus and circuitswhereby the present invention may conveniently be carried into effect.

Fig. 1 illustrates a space telegraph receiving system.

Figs. 2, 3, 4:, 5,6 and 7 illustrate inodifications of the presentinvention.

In the figures,

V is an elevated receiving conductor.

E is an earth connection.

M is a transformer whose primary and secondary windings are L and I2.

M is a transformer having the same primary winding as the transformer Mand whose secondary winding is 12.

IN "is a transformer whose primary and secondary windings are 1'1 and1'2.

C, C, G and C1 are condensers.

L is an auxiliary inductance coil.

L1 is an inductance coil.

K is a coherer or other suitable wave detector.

plete description of the construction of parts and the operation thereofthan is necessary to set forth herein, it being sufficient to state thatby means of the auxiliary inductance L the effect of the mutualinductance between the resonant receiving circuit 12 C C L and theelevated conductor system V 11 E is swamped and therefore the resonantreceiving circuit is rendered equivalent to a circuit having but asingle degree of freedom.

In Fig. 1 the means whereby natural rates of vibration are given theelevated conductor system which natural rates are made different fromthat of the associated resonant receiving circuit I2 C" C L is thecircuit C I2 inductively association with the primary winding 11 of thetransformer M. This circuit U 12 is equivalent in function to thecondenser C1 connected in parallel to the primary winding L of thetransformer M shown in Fig. 1 of myapplication Serial No. 193,371, filedFebruary 13, 1904:, now patent No. 767,99 because, as is wellunderstood, a system of two degrees of freedom such as that formed bythe circuitC 1'2 and the circuit V L E is the equivalent of a systemconsisting of a circuit such as V 11 E having the condenser Cconductively connected to the terminals of the coil 11, provided thecoil Lin such case be given an inductance equivalent to the apparentinductance of the primary winding 11 when inductively associated withits secondary winding 1'2. In fine, the condenser C reacts through themagnetic field of the transformer M upon the circuit V 11 E and thisreaction will be different for different frequencies of the impressedforce.

Careful consideration will show that the circuit C 12 employed forgiving the elevated conductor system natural rates of vibrationdifferent from that to which the associated resonant receiving circuitis responsive, inductively associated with the primary winding 11 whichis interposed in the vertical wire near its earth connection, will, incombination with said winding I1 and by its reaction thereon, present adefinite inductance reactance or capacity reactance for a predeterminedfrequency of impressed force and that said reactance will be differentfor different frequencies of the impressed force.

When the waves to be received are longer than those natural to theelevated conductor per se, i. e., when the frequency of the waves isless than the fundamental frequency of the elevated conductor per se,the reactance of the elevated conductor per se is a capacity reactance.

If therefore the waves to be received are longer than those natural tothe elevated conductor per se,the circuit C I2 may be so proportioned asto present, in combination with the primary winding 11 and by itsreaction there on, for the frequency of these waves an inductancereactance equivalent to that which would be given by a loading coiladapted to make the fundamental of the elevated cond uctor of afrequency equal to that of the waves to be received.

, The reactance offered by the elevated conductor system to theelectrical oscillations developed therein by a persistent train ofsimple harmonic waves the energy of which is to be received is thereforezero.

hen the waves to be received are shorter than those natural to theelevated conductor per se and not less than one-half the length of thosenatural to the elevated conductor per se, i. e., when the frequency ofthe waves is between the fundamental frequency of the elevated conductorper se and the first even harmonic of said fundamental frequency, thereactance of the elevated conductor per se is an inductance reactance.

If the waves to be received are shorter than those natural to theelevated conductor per se and not less than one half the length of thosenatural to the elevated conductor per se, the circuit C I2 may be soproportioned as to present, in combination with the primary winding I1and by its reaction thereon, for the frequency of these waves a capacityreactance equivalent to that which would be presented by a loadingcondenser adapted to make the fundamental of the elevated conductorequal to the frequency of the waves to be received.

Here again the reactance offered by the elevated conductor system to theelectrical oscillations developed therein by a persistent train ofsimple harmonic waves the energy of which is to be received is thereforeZero.

1 find by experience that when such proportions are given to theconstants of the inductively related circuit C 12 that it, incombination with the primary winding and by its reaction thereon, willpresent for the frequency of the waves to be received and to which theresonant receiving circuit is attuned a reactance equal and opposite tothe reactance of the elevated conductor per se,- the elevated conductorsystem in responding to electrical impulses of frequencies to which saidresonant receiving circuit is not attuned, or to abrupt or impulsiveelectrical forces, has developed in it natural oscillations offrequencies ill adapted to cause a response of the associated resonantreceivingcircuit, because the frequencies of said natural oscillationsare different from the frequency to which said resonant circuit isattuned.

In explanation of the foregoing, attention is again called to the factthat the closed secondary circuit 0 1'2 reacts upon the elevatedconductor system V L E when electromagnetic waves impinge upon saidelevated conductor system and create electrical oscillations thereinbecause no means, such as an auxiliary inductance coil, are provided forelimitating the effect of such closed secondary reaction and that,therefore, the system shown in Fig. 1 is functionally equivalent to thesystem shown in Fig. 1 of my aforesaid Letters Patent No. 767 ,994.Reference may therefore be had to said Letters Patent for a morecomplete explanation of the theory of operation of Fig. l of the presentapplication than is necessary to set forth herein.

I do not wish to be understood as confining myself to the specificarrangement shown in Fig. 1 because it will be obvious to those skilledin the art that there are many other arrangements in which theinductively associated circuit C Y2 may be employed for carrying out thehereinbefore stated objects of this invention. For example as shown inFig. 2 said circuit may be employed with the systems described in myapplication Serial No. 182,632, filed November 25, 1903, now patent No.767,984, in which the auxiliary inductance coil L of the resonantreceiving circuit is eliminated and the windings ofthe transformer M areso spatially related as to cause the resonant receiving circuit tovibrate as a system having but a single degree of freedom; or as shownin Figs. 3 and 4 it may be employed with the systems described in myapplications Serial Nos. 185,872 and 185.873 filed December 19, 1903,now patents Nos. 767,989 and 767,990 in which the resonant receivingcircuits are conductively connected to the elevated receiving conductorin such manner that the self energy of each of the conductivelyconnected circuits is great as compared to the mutual energy of eachcircuit with respect to the other. In cases of conductive connection ofthe resonant receiving circuit to the terminals of a condenser asdescribed in said application Serial No. 185,873, now patent No.767,990, it is necessary to provide a primary winding 11 seriallyconnected with the elevated conductor either directly above or below thesaid condenser as shown in Fig. 4. Also the system shown in Fig. 1 maybemodified as shown in Fig. 5 by providing a secondary primary winding I1for the secondary 1'2 of the circuit 0' 1'2 either directly above orbelow the primary winding L of said Fig. 1 and such second primarywinding I1 may also be employed when the circuit C 1 2 is used as shown,respectively, in Figs. 6 and 7 in connection with the systems describedin my applications Serial Nos. 182,632 and 185,872 now patents Nos. 767,984 and 767,989 aforesaid.

Although I have described the wave detector K as a coherer it is obviousthat any other suitable receiver such as a bolometer fine wire or stripK may be used in the manner shown in Fig. 7 of my application Serial No.193,371 filed February 13, 190%. now patent No. 767,994. It is obviousthat many other modifications may be devised by those skilled in the artwithout departing from the spirit of my invention.

I make no claim in this application for the herein disclosed methodswhich may be carried into effect by the apparatus herein claimed,inasmuch as such methods constitute the sub ject matter of my divisionalapplication Serial No. 244,350, filed Feb. 6, 1905.

I claim 1. Asa means for preventing a resonant receiving circuit of aspace telegraph receiving system from responding to extraneous electrical impulses of a frequency to which said resonant receiving circuitis not attuned or to abrupt or impulsive electrical forces, a resonantreceiving circuit attuned to the frequency of the waves the energy ofwhich is to be received, an elevated receiving conductor systemassociated with said resonant receiving circuit and a circuit,containing a condenser, inductively associated with said elevatedreceiving conductor system and so designed as to give the elevatedreceiving conductor system natural rates of vibration different fromthat of the associated resonant receiving circuit.

2. In a space telegraph receiving system, a resonant receiving circuitattuned to the frequency of the waves the energy of which is to bereceived, a receiving conductor associated with said resonant receivingcircuit, and a circuit, containing a condenser, ind uctively associatedwith said receiving conductor.

3. In a space telegraph receiving system, a resonant receiving circuitattuned to the frequency of the waves the energy of which is to bereceived, a receiving conductor associated with said resonant receivingcircuit, and a circuit, containing capacity and inductance, inductivelyassociated with said receiving conductor.

4. In a space telegraph receiving system, a receiving circuit attuned bycapacity and inductance to the frequency of the waves the energy ofwhich is to be received, a receiving conductor associated with saidreceiving circuit, and a circuit, containing capacity and inductance,inductively associated with said receiving conductor.

5. In a space telegraph receiving system, a resonant receiving'circuitattuned to the frequency of the waves the energy of which is to bereceived, a receiving conductorinductively associated therewith, meansfor rendering the resonant receiving circuit the equivalent of a circuithaving but a single degree of freedom, and a circuit, containing acondenser, inductquency of the waves the energy of which is to bereceived, a receiving conductor associated therewith, means forrendering the resonant receiving circuit the equivalent of a circuithaving but a single degree of freedom, and a circuit, containing acondenser, inductively associated with said receiving conductor.

7. In a space telegraph receiving system, a resonant receiving circuitattuned to the frequency of the waves the energy of which is to bereceived, areceiving conductor associated therewith and adapted topresentfor impressed forces of said frequency an inductance reactance,and a circuit, containing capacity and inductance, inductivelyassociated with the receiving conductor system and so designed as topresent, by its reaction on said receiving conductor system forimpressed forces of said frequency, a capacity reactance equivalent tothat which would be presented by a loading condenser adapted to make thefundamental of said receiving conductor system of a frequency equal tothat of the waves to be received and thereby to balance the inductancereactance of the receiving conductor per se for impressed forces of saidfrequency.

8. In a space telegraph receiving system, a resonant receiving circuitattuned to the frequency of the waves the energy of which is to bereceived,a receiving conductor associated therewith and adapted topresent for impressed forces of said frequency a definite reactance, anda circuit, containing capacity and inductance, inductively associatedwith the receiving conductor system and so designed as to present, byits reaction on said receiving conductor system for impressed forces ofsaid frequency, a, reactance equal and opposite to the reactance of thereceiving conductor per se and thereby to balance the reactance of saidreceivin conductor per se for impressed forces of sai frequency.

9. In a space telegraph receiving system,

' a resonant receiving circuit attuned to the frequency of the waves theenergy of which is to be received,areceiving conductor inductivelyassociated therewith and adapted to present for impressed forces of saidfrequency a definite reactance, and a circuit, containing a condenser,inductively associated with the receiving conductor system and sodesigned as to present, by its reaction on said receiving conductorsystem for impressed forces of said frequency, a reactance equal andopposite to the reactance of the receiving conductor per se and therebyto balance the reactance of said receiving conductor per se forimpressed forces of said frequency. 10. As a means for preventing aresonant receiving circuit of a space telegraph receiving system fromresponding to extraneous electrical forces of a frequency to which saidresonant receiving circuit is not attuned, or to abrupt or impulsiveelectric forces, and for assisting said resonant circuit to respond topersistent forces of the frequency to which said circuit is attuned, thecombination of a resonant receiving circuit attuned to the fre quency ofthe waves the energy of which is to be received, an elevated receivingconductor system associated with said resonant receiving circuit, and acircuit, containing a condenser, inductively associatedwith saidelevated receiving conductor system and so designed that it shall by itsreaction on the elevated conductor system cause the elevated conductorsystem to have zero reactance for electrical oscillations developedtherein by a persistent force acting thereon and of the frequency towhich said resonant receiving circuit is attuned.

In testimony whereof I have hereunto subscribed my name this 16th day ofFebruary, 1904.

JOHN STONE STONE.

l/Vitnesses:

BRAINERD T. JUDKINs, G. ADELAIDE Hreerns.

